For more than eight years, scientists have been doing fieldwork on Mars in the first overland investigation of another planet. Working through programmed robotic laboratories, called the Mars Exploration Rovers, they have a virtual experience of being on Mars. The Spirit and Opportunity teams have driven over 25 miles, taken thousands of photographs, analyzed the chemistry of the terrain, and inspected rocks by grinding them and taking microscopic images. How does working remotely through a robotic laboratory change the nature of field science? How does it change the scientists? A cognitive scientist with privileged access to mission operations, Clancey explains that the “robotic geologists” are not the rovers, but the scientists who have imaginatively projected themselves into the body of the machine.